Feeder tube cylinder



Sept. 21, 1965 1'. R. HALL 3,207,044

FEEDER TUBE CYLINDER Filed May 20, 1963 2 Sheets- Sheet 1 INVENTOR. THOMAS R. HALL A iiorney Sept. 21, 1965 T. R. HALL FEEDER TUBE CYLINDER 2 Sheets- Sheet 2 Filed May 20, 1963 R 0 m MH R m M w T BY 12 4 W Atarney United States Patent O 3,207,044 FEEDER TUBE CYLINDER Thomas R. Hall, Vancouver, Wash. (1113 Andrix Court, Concord, Calif.) Filed May 20, 1963, Ser. No. 281,640 19 Claims. c1.91 414 This invention relates to a double acting fluid pressure cylinder having a novel feeder tube arrangement, for positioning and supplying and exhausting a second fluid pressure operated device from a hollow piston rod extending from the cylinder.

The invention is of general application but is of particular advantage in connection with devices operated by fluid pressure motors on the end of an extensible boom. For example, a hoist drum operated by a reversible fluid pressure motor may be mounted on the end of an extensible derrick boom. Heretofore, it has been necessary to supply such motor with flexible fluid conduits which require some means for taking up the slack in the conduits when the boom is retracted. It is highly desirable to dispense with the flexible conduits and, particularly, to obviate the necessity for slack take-up means for handling the excess length of conduits when the boom is retracted.

The general object of the present invention is, therefore, to provide means for positioning and supplying and exhausting a fluid pressure operated device on an extensible piston rod in a fluid pressure cylinder without the use of flexible conduits.

Further objects are to provide means for the purpose described, utilizing a hollow piston rod and a feeder tube in the cylinder, to provide a feeder tube arrangement through the body of a cylinder and piston unit itself, to provide a hydraulic circuit through a hydraulic cylinder and piston rod functionally independent of the hydraulic circuit for the cylinder, to provide an improved extensible boom derrick having a hydraulic motor mounted on the end of the boom, and to provide an extensible boom derrick having a pair of hydraulic motors on the boom.

The foregoing and other objects and advantages will become apparent and the invention will be better understood from the following description of the preferred embodiment illustated in the accompanying drawings. Various changes may be made, however, in the details of construction and arrangement of parts and all such modifications within the scope of the appended claims are included in the invention.

In the drawings:

FIGURE 1 is a side elevation view of a derrick embodying the principles of the invention;

FIGURE 2 is a sectional view of the derrick boom including its fluid pressure system;

FIGURE 2A is a diagram of the valve arrangement in the fluid pressure system using conventional symbols; and

FIGURE 3 is a cross sectional view taken on the line 33 of FIGURE 2.

In FIGURE 1 the derrick boom is mounted on a base pedestal 11 on the rear corner of a truck 12. The pedestal is provided with an outrigger hydraulic ram 13 equipped with a ground shoe 14 to stabilize the derrick and take the major portion of the derrick load ofl the truck spring. A similar outrigger stabilizer is preferably provided on the other side of the truck (not shown). The derrick boom is mounted for lateral swinging movements on the pedestal. For this purpose, the boom base member 15 may be equipped with a worm in mesh with a worm gear on pedestal 11, the Worm being rotatable by a worm shaft 16 which is adapted to receive a crank or other suitable means for turning it.

A lower boom section 20 is pivotally mounted at 21 on the boom base 15. An upper boom section 22 telescopes within the lower section 20. The boom may be "ice raised and lowered by a conventional hydraulic ram 23 which is pivotally connected at 24 with the boom base 15. A piston rod extending from the upper end of the ram is pivotally connected with a bracket 25 on the boom section 20. Mounted on the outer end of boom section 22 is a reversible hydraulic motor M associated with a hoist drum or other power operated device.

It is often desirable to provide a second power operated device on the boom as, for example, an augur or post hole digger 30. The augur 30 is rotated by a reversible hydraulic motor M which hangs from a slide 31 on the upper boom section 22. The augur may be extended and retracted along boom section 22 by a piston rod 32 in a double acting hydraulic cylinder 33. Cylinder 33 is rigidly mounted at 34 on the lower boom section 20.

Piston rod and cylinder 32, 33 have a novel form of construction embodying important features of the invention and the boom sections 22, 20 house a similar novel piston rod and cylinder construction, the latter being illustrated in longitudinal section in FIGURE 2.

In the present derrick the boom sections 20, 22 are rectangular in cross section, the lower section containing and being rigidly connected with a double acting cylinder 35, and the upper section containing and being rigidly connected with a tubular piston rod 36. The inner or left end of cylinder 35 is closed by a head 37 which has a central fluid connection 38 communicating with a tube 40 mounted on the head. The outer or right end of cylinder 35 is closed by a head 41 which has a circular seal 42 engaging the piston rod tube 36.

Piston rod tube 36 is connected with its piston 43. The piston has an outer sealing ring 44 engaging the inside of cylinder 35 and is centrally apertured and provided with an inner sealing ring 45 engaging the outer surface of tube 40. Also connected with the piston is an inner piston rod tube 46 within which the tube 40 extends. The outer ends of the piston rod tubes are closed by a head 47 which is centrally apertured to provide a fluid connection 48 for the motor M The cylinder and piston rod construction just described forms a plurality of fluid chambers. The cylinder 35 has an inner end chamber A which is equipped with an external fluid connection 50 to admit fluid pressure for eX- tending the piston rod. On the other side of the piston, the cylinder 35 contains an outer end chamber B with an external connection 51 for supplying fluid pressure to retract the piston rod. Between the two piston rod tubes 36 and 46 is an annular fluid chamber C, and within the inner tube 46 is another fluid chamber D. Outer tube 36 has one or more port openings 52 at its inner end interconnecting chambers B and C. The outer end of tube 36 is provided with a fluid connection 53 for the motor M The external fluid circuit comprises a conduit 60 from connection 50, a conduit 61 from connection 38 and a conduit 62 from connection 51. These three conduits are all connected with a control valve unit 65 which is supplied by pump P from a hydraulic reservoir or tank T. Discharge from cylinder 35 and motor M returns to the tank through a conduit 66.

In FIGURE 2A, the valve unit 65 is shown by conventional symbols as two separate three-position, fourconnection manual valves for convenience in tracing the fluid circuits. It is to be understood, however, that the various valve functions to be described may be performed by a single combined valve or by different types of valves which are effective to perform the necessary functions. In FIGURE 2A a boom valve controls extension and retraction of the boom, and a motor valve 71 starts, stops and reverses the hydraulic motor M Ordinarily, the first hydraulic operation is to extend the boom. This is accomplished by moving boom valve 70 to the right, making conduit 60 a pressure line and conduit 62 a return or discharge line. Thus, fluid pressure is supplied to chamber A causing the piston 43 to move outward to the right, discharging liquid from chamber B through conduit 62 to tank T. When the boom has been sufliciently extended, valve 70 is returned to its middle position shown whereby the piston is hydraulically locked against movement in either direction.

In order to operate motor M forward, motor valve 71 is moved to the right making conduit 61 a pressure line and conduit 62 again a discharge line. Hydraulic pressure is then delivered through tube and chamber D to the motor and discharged from the motor through chamber C, port 52 and chamber B to discharge line 62 The hydraulic lock on the outer end of piston 43 is thereby relieved but there is no tendency for the piston to move outward because chamber A remains sealed by the closed position of boom valve 70.

If desired, the boom may be extended while motor M is running forward. The shifting of boom valve 70 to the right to extend the boom does not interfere with the forward operation of the motor. Suitable stop means are provided to limit the extension of the piston rod so that ports 52 will not be closed by seal 42.

Reverse operation of motor M is produced by shifting motor valve 71 to the left. Then conduit 62 is the pressure line and conduit 61 is the discharge line. Pressure in line 62 is transmitted through chamber B, port 52 and chamber C to the motor in reverse direction and the motor discharge passes through chamber D and tube 46 back to the line 61. The introduction of pressure into chamber B does not disturb the boom because chamber A on the opposite side of piston 43 is closed and sealed at boom valve 70. Thus, the motor M may be started, stopped and reversed without disturbing the position of upper boom section 22.

When it is desired to retract the boom, boom valve 79 is shifted to the left. This again makes conduit 62 .a pressure line and conduit 60 a discharge line. Pressure is transmitted from conduit 62 into chamber B and fluid is discharged from chamber A into conduit 6%. Motor M is not aflected by extension or retraction of the boom as long as motor valve 71 remains in its central off position, closing the end of conduit 61. If desired, however, the motor may be operated in reverse while the boom is being retracted. Conduit 62 then supplies both chamber B and the motor. Motor discharge returns through conduit 61 .and chamber A discharge returns through conduit 60, both of which are then open to the tank T through the valves 70 and 71 both in left positions.

Piston rod 32 and cylinder 33 are constructed the same as the piston rod and cylinder in FIGURE 2, lacking merely the structural boom tubes 22, 20, and similar conduit and valve arrangements are provided. The end of piston rod 32 has a fluid connection 48a similar to connection 43 in FIGURE 2 supplying fluid pressure for forward rotation of motor M A connection 53a similar to 53 supplies fluid pressure for reverse rotation. Cylinder 33 has fluid connections Sfla, 51a and 61a corresponding to 50, 51 and 61, respectively.

After boom section 22 has been extended, the slider 31 may be extended to a desired position and motor M may be started, stopped and reversed. When the derrick is mounted on the back end of a truck as shown, the retraction of the boom permits it to be swung over the cab of the truck for transportation without projecting beyond the front end of the truck, and when the boom is extended it will afford suflicient reach in all directions to accomplish its intended work. Flexible hydraulic conduits and slack take-up means associated with the boom extension are eliminated.

Ordinarily, it is not necessary to operate either motor M or M while it is being extended or retracted, thus making it convenient to combine the two valves 70 and 71 into a single valve unit when desired. Two separate valves are shown primarily to simplify the explanat n of the fluid circuit so that the principles of the invention may be more readily understood.

The present fluid pressure system is suitable for either hydraulic fluid or compressed air. In either case the system is not limited to use with rotary motors but may be used to provide .a pressure fluid circuit for any purpose whatsoever. As another example, it is often useful to supply fluid pressure for operating portable hydraulic or pneumatic tools in operations Where it would be inconvenient to use long flexible hose conduits extending all the way back to the pump or compressor. Such tools and devices do not have to be supported by the boom in order to utilize the important advantages of the invention.

Having now described my invention and in what manner the same may be used, what I claim as new and desire to protect by Letters Patent is:

1. A double acting fluid pressure cylinder and piston unit having a piston rod with fluid passageways therein, a reversible fiuid pressure operated unit having inlet and outlet connections with said piston rod, and means in said cylinder and piston rod to operate both of said units individually from external supply connections with said cylinder.

2 A double acting cylinder, a piston in said cylinder having a hollow piston rod, a reversible fluid pressure operated device supplied through said piston rod, a fluid connection in the inner end of said cylinder communicating with the inner end cylinder chamber, a fluid connection for said device in the inner end of said cylinder and communicating with said piston rod, and a fluid connection in the outer end of said cylinder communicating with the outer end cylinder chamber and said piston rod.

.1. A cylinder, a head in one end of said cylinder, a fluid connection in said end of said cylinder, a piston in said cylinder, a piston rod on said piston extending out of the other end of said cylinder, said piston rod comprising inner and outer concentric tubes, a head in said outer end of said cylinder surrounding said piston rod, a centralfluid connection in said first head, a tube connected with said first head in communication with said central connection and extending through said piston into sa d inner tube of said piston rod, a fluid connection in said other end of said cylinder, a port in said outer piston rod tube adjacent said piston, a head closing the outer ends of both piston rod tubes, a fluid connection in said last head communicating with said inner tube, and a fluid connection in the outer end portion of said outer tube.

4. An extensible boom for supplying a reversible fluid pressure operated device, comprising lower and upper telescopic boom sections, said lower boom section including a double acting cylinder and said upper boom section includinga piston rod in said cylinder, inlet and outlet fluid connections n the outer end of said piston rod for said device, a pair of passageways extending from said connections longitudinally through said piston rod a fluid connection communicating with the inner end of said cylinder, a fluid connection in said cylinder communicating with one of said piston rod passageways, and a fluid connection in said cylinder communicating with the outer end of said cylinder and the other of said piston rod passageways.

5. An extensible boom for carrying a fluid circuit comprising telescopic lower and upper boom sections said lower boom section including a double acting cylinder and said upper boom section including a piston rod in said cylinder, inlet and outlet fluid connections for said fluid circuit in said piston rod, and means in said piston rod and cylinder for supplying said connections from said cylinder.

6. A derrick comprising an extensible boom having telescopic lower and upper boom sections, said lower section including a double acting cylinder and said upper section including a hollow piston rod in said cylinder, a

reversible fluid motor on the outer end of said upper boom section, inlet and outlet fluid connections in said piston rod for operating said motor, fluid connections in said cylinder for operating said piston rod and motor individually, and means interconnecting said piston rod fluid connections with said cylinder fluid connections, all within said cylinder and piston rod.

7. A derrick having an extensible boom, said boom comprising telescopic lower and upper boom sections, said lower boom section including a double acting cylinder and said upper boom section including a piston rod in said cylinder, a reversible fluid pressure operated device on the outer end of said upper boom section, inlet and outlet fluid connections for said device in said piston rod, a double acting cylinder on said lower boom section having a piston rod, a reversible fluid pressure operated device mechanically connected with said second piston rod and supported for sliding movement on said upper boom section, and inlet and outlet fluid connections for said second device in said second piston rod.

8. A derrick having an extensible boom, said boom comprising telescopic lower and upper boom sections, a double acting cylinder on said lower boom section having a piston rod, a reversible fluid pressure operated device mechanically connected with said piston rod and supported for sliding movement on said upper boom section, and inlet and outlet fluid connections for said device in said piston rod.

9. A double acting cylinder, a piston in said cylinder having a hollow piston rod, a reversible fluid pressure operated device supplied through said piston rod, and fluid pressure and discharge connections in said cylinder for said cylinder and said device, said device being reciprocable by said piston rod.

10. The structure of claim 9, including upper and lower boom sections, said upper boom section being extendable and retractable by said piston rod, and said device being carried by said upper boom section.

11. The structure of claim 1, said section unit being reciprocable by said piston rod.

12. The structure of claim 11, including upper and lower boom sections, said upper boom section being extendable and retractable by said piston rod, and said second unit being carried by said upper boom section.

13. The structure of claim 2, said device being reciprocable by said piston rod.

14. The structure of claim 13, including upper and lower boom sections, said upper boom section being extendable and retractable by said piston rod, and said device being carried by said upper boom section.

15. The structure of claim 3, including a fluid pressure operated device reciprocable by said piston rod and supplied by said fluid connections in the outer end of said piston rod.

16. The structure of claim 15, including upper and lower boom sections, said upper boom section being extendable and retractable by said piston rod, and said device being carried by said upper boom section.

17. A double acting cylinder, a piston in said cylinder having a piston rod with a pair of longitudinal passages therein, .a reversible fluid pressure operated motor reciprocable by said piston rod and having fluid inlet and outlet connections with said piston rod passages, fluid connections in said cylinder and piston rod, a fluid pressure supply, a valve unit, and external fluid connec tions between said cylinder, valve unit and supply arranged to operate said piston and motor individually.

18. The structure of claim 17, including upper and lower boom sections, said upper boom section being extendable and retractable by said piston rod, and said motor being carried by said upper boom section.

19. A double acting cylinder having a piston and a piston rod with a pair of longitudinal passages therein, said passages having connections in the outer end of the piston rod for an external fluid circuit, said cylinder having a rod end and an opposite end, one of said passages communicating with said rod end of the cylinder, a tube mounted in said opposite end of the cylinder and extending slidably through said piston and communicating with the other passage, and external fluid connections to said tube, said rod end of the cylinder and said opposite end of the cylinder, said cylinder having a fluid operating circuit through its two end connections for reciprocating said piston without energizing said external fluid circuit, and said external fluid circuit having fluid connections througth said tube and said rod end of the cylinder for energizing said external fluid circuit without actuating said piston.

References Cited by the Examiner UNITED STATES PATENTS 1,237,338 8/17 Hogg 92-110 1,324,078 12/ 19 Smith 91-61 1,388,406 8/21 Clark 9161 1,455,553 5/23 Slater 91--61 2,048,978 7/36 Tait 92110 2,886,005 5/59 Bryan 921l1 3,044,635 7/62 Kirstein 2 12--55 3,073,455 1/63 Eckels et a1. 2l255 3,093,248 6/63 Winter 2l255 3,168,853 2/65 Prince 921 10 SAMUEL LEVINE, Primary Examiner.

HUGO SCHULTZ, FRED E. ENGELTHALER,

Examiners. 

1. A DOUBLE ACTING FLUID PRESSURE CYLINDER AND PISTON UNIT HAVING A PISTON ROD WITH FLUID PASSAGEWAY THEREIN, A REVERSIBLE FLUID PRESSURE OPERATED UNIT HAVING INLET AND OUTLET CONNECTIONS WITH SAID PISTON ROD, AND MEANS IN SAID CYLINDER AND PISTON ROD TO OPERATE BOTH OF SAID UNITS INDIVIDUALLY FROM EXTERNAL SUPPLY CONNECTIONS WITH SAID CYLINDER. 